Zhou Shifeng, a lawyer formerly managing the Fengrui Law Firm, was convicted of subverting state power and sentenced to seven years in prison Thursday.
He was also deprived of his political rights for five years, according to a ruling handed down Thursday by the No. 2 Intermediate People's Court in Tianjin Municipality.
Zhou, 51, pled guilty and told the court he would not appeal.
Two other men connected to Zhou's activities were sentenced by the same court on Tuesday and Wednesday.
More than 40 people, including lawyers and journalists from home and overseas, observed Thursday's trial. None of Zhou's relatives were present, at his request.
Zhou is originally from Anyang City, Henan Province. He was director of the Beijing-based Fengrui Law Firm, which was suspended from operation in 2015 after a police investigation into several of its employees.
Zhou has long been influenced by anti-China forces and gradually established ideas to overturn the country's political system, said a court statement.
Since 2011, Zhou has attacked the socialist system and the "one country, two systems" policy that applies to Hong Kong and Macao, the two special administrative regions, and incited confrontation, the statement said.
He used the law firm as a front for his subversive agenda, recruited like-minded lawyers and other staff and together they discredited judicial organs, attacked the judicial systems and promoted anti-government sentiment by interfering in and exaggerating sensitive cases.
Along with members of an illegal religious organization, paid protestors, lawyers and others, he plotted and established "strategies, methods and steps" to subvert state power and carried out a series of subversive activities, which endangered national security and social stability, it said.
"I plead guilty," Zhou said in his final statement, "My actions have brought instability and risks to society."
Zhou hired two attorneys, who met with him multiple times before the trial. A pre-trial conference was also held to hear the opinions of the prosecution and defense teams.
During the trial, prosecutors presented evidence and witness testimonies, and the defence team did not object.
According to a prosecution witness, Zhou had recruited two administrative assistants, surnamed Wu and Liu, who actually acted as Zhou's "civil and martial go-getters."
"Liu's duty was to analyze sensitive cases and to identify loopholes, while Wu was responsible for promoting them," said Huang who used to work in Zhou's firm, adding neither were lawyers.
Zhou hired them to distort facts, cause confusion and social instability, and attack the country's judicial system, according to Huang.
In March 2015, while a local court in Hebei Province was hearing an extortion case taken on by Zhou's firm, he instructed lawyers to take pictures of prosecutors and judges and posted them online, fabricating rumors on and questioning their moral characters.
Another case used by Zhou occurred in May 2015, when police officer Li Lebin shot dead Xu Chunhe after Xu had continued to attack the police officer despite multiple warnings. CCTV cameras and follow-up investigations confirmed that Li had acted within the law.
Zhou instructed his employees to post online articles that distorted the facts in an attempt to influence public opinion and misrepresent the incident as police brutality.
In a gathering in a Beijing restaurant in February 2015, Zhou and other suspects talked about how to oppose the Party and the socialist system, according to Gou Hongguo, who is expected to stand trial in connection with this case.
According to Gou, Zhou said "add some fire wood and load more sand to expedite the sinking of the giant ship of the government."
Zhou said his activities such as disrupting judicial orders aroused the interests of some overseas forces.
"They've been actively wooing me, and want to use us to challenge court hearings and China's entire judicial system, making trouble for the Chinese government," he confessed, adding that these outside forces want to overturn the leadership of the Communist Party of China.
"China will never allow anyone to forge evidence, disrupt judicial work, conceal the truth or instigate hatred for the government ... nor will it allow anyone to carry out subversive action in the name of 'rights safeguarding,'" the prosecutors said during the trial.